title: [Influencing factors and mechanism of arsenic removal during the aluminum coagulation process].
abstract: Aluminum coagulants are widely used in arsenic (As) removal during the drinking water treatment process. Aluminium chloride (AlCl3) and polyaluminium chloride (PACl) which contains high content of Al13 were used as coagulants. The effects of aluminum species, pH, humic acid (HA) and coexisting anions on arsenic removal were investigated. Results showed that AlCl3 and PACl were almost ineffective in As(II) removal while the As(V) removal efficiency reached almost 100%. pH was an important influencing factor on the arsenic removal efficiency, because pH influenced the distribution of aluminum species during the coagulation process. The efficiency of arsenic removal by aluminum coagulants was positively correlated with the content of Al13 species. HA and some coexisting anions showed negative impact on arsenic removal because of the competitive adsorption. The negative influence of HA was more pronounced at low coagulant dosages. PO4(3-) and F(-) showed marked influence during arsenic removal, but there was no obvious influence when SiO3(2-), CO3(2-) and SO4(2-) coexisted. The present study would be helpful to direct arsenic removal by enhanced coagulation during the drinking water treatment.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. chen4189@163.com
authors.forename: Gui-Xia
authors.initials: GX
authors.lastname: Chen
authors.forename: Cheng-Zhi
authors.initials: CZ
authors.lastname: Hu
authors.forename: Ling-Feng
authors.initials: LF
authors.lastname: Zhu
authors.forename: Hua-Qing
authors.initials: HQ
authors.lastname: Tong
mesh_terms: D000327:Adsorption; D000535:Aluminum / Q000737:chemistry*; D000077410:Aluminum Chloride; D017607:Aluminum Compounds / Q000737:chemistry; D000536:Aluminum Hydroxide / Q000737:chemistry; D001151:Arsenic / Q000302:isolation & purification*; D002712:Chlorides / Q000737:chemistry; D060766:Drinking Water / Q000032:analysis; D005427:Flocculation; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D017607:Aluminum Compounds; D002712:Chlorides; D060766:Drinking Water; D014874:Water Pollutants, Chemical; C016213:aluminum oxychloride; D000077410:Aluminum Chloride; D000536:Aluminum Hydroxide; D000535:Aluminum; D001151:Arsenic